XML 592 R112.htm IDEA: XBRL DOCUMENT v3.20.4
Impairment charges - Summary of impairment charges (Detail) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   $ (1,243) $ (3,487) $ (132)
Impairment charges, Tax   128    
Impairment charges, Non-controlling interests   0 1,506 3
Impairment charge, net amount   (1,115) (1,658) (104)
Impairment loss recognised in profit or loss   904 3,487 132
Impairment charges related to EAUs (pre-tax)   (368) 0 0
Impairment charges   (1,272) (3,487) (132)
Taxation (including related to EAUs)   157 323 25
Intangible assets        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (4) (1) (2)
Property, plant and equipment        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (900) (3,486) (130)
Investment in equity accounted units ("EAUs")        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge     0 0
Aluminium | Pacific Aluminium        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (489) 0
Impairment charges, Tax   17    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   (472)    
Aluminium | Pacific Aluminium | Investment in equity accounted units ("EAUs")        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (339)    
Aluminium | Sohar        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (220) 0 0
Impairment charges, Tax   0    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   (220)    
Aluminium | Sohar | Investment in equity accounted units ("EAUs")        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Impairment loss recognised in profit or loss $ 220      
Aluminium | ISAL        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (93) (109) (123)
Impairment charges, Tax   (38)    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   (131)    
Aluminium | Yarwun Alumina Refinery        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   0 (1,138) 0
Impairment charges, Tax   0    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   0    
Impairment loss recognised in profit or loss     1,138  
Copper & Diamonds | Diavik        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   (441) 0
Impairment charges, Tax   149    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   (292)    
Copper & Diamonds | Oyu Tolgoi        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   0 (2,240) 0
Impairment charges, Tax   0    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   0    
Energy & Minerals | Rossing        
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]        
Total impairment charge   0 $ 0 $ (9)
Impairment charges, Tax   0    
Impairment charges, Non-controlling interests   0    
Impairment charge, net amount   $ 0